The Siwa Oasis is famous for its olives and sweet dates. The oasis sits on the border of the Egyptian Sand Sea. It is believed the unique minerals in the water of the Siwa Oasis, combined with saline soils, produce the sweet, large dates.
Siwa is also famous for the ancient oracle temple of Amun. Alexander the Great made the journey to Siwa before embarking on his campaign to conquer Persia.
The dates are also sold stuffed with almonds and chocolate. If you're lucky enough to make it to Siwa, shops specializing in dates are located around Market Square, and prices range from around 7 to 8 LE for a 500 gram box.
Dianabuja, on her blog, gives a great background to the food of Siwa Oasis, including some gorgeous local recipes using dates and olives.